%0 Generic %A Michael, Nikolaos A. %A Carter, Andrew %A Whittaker, Alexander C. %A A. Allen, Philip %D 2016 %T Erosion rates in the source region of an ancient sediment routing system: comparison of depositional volumes with thermochronometric estimates %U https://geolsoc.figshare.com/articles/dataset/Erosion_rates_in_the_source_region_of_an_ancient_sediment_routing_system_comparison_of_depositional_volumes_with_thermochronometric___estimates/3453665 %R 10.6084/m9.figshare.3453665.v1 %2 https://ndownloader.figshare.com/files/5423621 %K time interval %K provenance methods %K Pyrenean Axial Zone %K source areas %K depositional volumes %K catchment erosion rates %K 7.7  myr period %K detrital apatites sampling %K year time scale %K Average exhumation rates %K thermochronometric estimates Calculation %K source regions %K erosion rate %K depositional volume %K Sediment supply %K mm %K Eocene time period %K catchment expansion %K source region %K thermochronological methods %K grain size %K Erosion rates %K Geology %X

Calculation of the total depositional volume of an ancient source-to-sink system, combined with estimates of the area of catchments acting as source regions using provenance methods, is used to evaluate average catchment erosion rates on a million year time scale. These rates are compared with values derived from thermochronological methods. Using the mid- to late Eocene (33.9–41.6 Ma) Escanilla palaeo-sediment routing system from the south–central Pyrenean orogenic wedge-top zone as an example, c. 3500 ± 300 km3 of solid particulate sediment was derived from two catchments in the south–central Pyrenees over a 7.7 myr period, equivalent to a mean erosion rate of c. 0.15–0.18 mm a−1. Average exhumation rates in contributing catchments over the same time interval are estimated at 0.2–0.3 mm a−1 based on apatite fission-track analysis of pebbles in proximal conglomerates, and 0.23–0.34 mm a−1 from fission-track analysis of detrital apatites sampling a wider range of grain size. Sediment supply progressively increased during the mid- to late Eocene time period, at least in part driven by catchment expansion deep into the Pyrenean Axial Zone at c. 39 Ma. The consistency of the rates of catchment-averaged erosion calculated from different methods builds confidence that source areas have been connected to depositional sinks correctly.

%I Geological Society of London